Artificial limb



D. W. DORRANCE.

ARTIFICIAL LIMB.

APPLICATION FILED em. 19, 1920.

1,387,133. Patented Aug. 9, 1921.

A ll VIIIII/II III/ [T951 ZM 6 9210M- ATTORNEY l7 UNITED STATES.

. DAVID w. DORRAIN'CE, or slim JOSE, enmromvm.

" ARTIFICIAL- LIME},

. I To all whom it Mycbmem:

Be it known "that I, DAVID-W; DORRANOE, a citizen of the United States; residing at San Jose, in the county of'Santa Clara and State of California, have invented'new and useful Improvements in Artificial Limbs, of

which the following is a specification;

This invention relates to artificial limbs, especially an elbow lock for artificial arms;

1 e; construction of artificial arms, and

espe 'zially such [as employed fin" an elbow joint, considerable trouble is encountered when the wearer attempts to employ certain tools o-r to accomplish certain work.

This isdue to the factthat' the 'elb w joints in general 'use' are not sufliciently substantial and do not permit any force to be applied. Varying forms of "friction joints and locks have been employed to, overcome erated.

this difliculty, but they are readily pp- One of the objects of the present invention is .to overcomethe difiiculties specified by providing an elbow lock which is'inot only simple and substantialfin construction but 'jwhi h may be readily and ,q e y br I Fig. 2 s across section "0n line 2-2,

Another, object of the invention is to provide an elbow lock, ,whic'h' permits; free movement of the arm. andwhich permits locking of the" elbow joint in any position desiredl 7 The invention consists of the parts and the construction, combination and arrangement of parts ashereinafter'more fully described and claimed, having 'r'eference tothe accompanying drawings, in which-'- j ,Figure 1 is a longitudinal section of an artificial arm showing the application of the elbow lock 7 Fig.1. p I 7 j .FigJ-B is, an enlarged longitudlnal'sectlon ar s guided ndloeked Specification of Letters Patent. 7 Application/filed October 19,: i920; steal n 1417,991

- about which the elbow. joint s'vvlngs,"-

a i ur t ly"m i n edibtwee amber: members a'n'd supported by itheifsame' 1 4 esteem o fl fcy dtii 3.

"cal pawl;

"se ti n partiauy enters'tlielowje Se? 0 It i indie 'cb nec t rw hty pi 2 aboutf whlch theilo'wer sectioniswings this "$1 i 'e j s i d iw'vl in f he lov H Sect on B 1s a pair: of be ringamembers cylindrical. pawl -Eiiter'iding thrOL gHith e .cylindi' ical' .pawl:is'a rodf5,andisecurecl to the upperf L. end "thereo flf and pro'ect'ing through a slot 6 inthe arm'sfectibnlB taining the cylindrical p'av'vlj locking I Formed in thejpppesite sides of the 'cypawl proper is' a .rack f bar 'llbn whichtare V, I A formed'i'teeth 121,1 Tissue-saris pivot@1iy'-" Another object oftheinvention'is to 'pro- 'vide an elbow joint which automatically locks itself, and which may ,be' released either by ,should e'r novement or by a releasing lever, as will hereinafter-"be described;

' Further objects will hereinafter appear.

attached "to section ijAjas ,at' l4: and forms, in conjunction with the cylindribal pawl,- a' locking mechanism whereby the lower .arrn section B may be "secured at any .1 f

point i1 telrmediate to that showiiihlligijl and aright angular position.- Infother w'ords,'the' lower arm section Bhasalmove- 'nient of approximately 90? mayfbe practically locked at any'intermediatepoint To permit fr'ee' sliding movement of the" ide plate 15. This plate BX-V by a. suppbrpingg late "17: Thisp'late V V I V disposed 'in 'frontjofthe forward-slot 10 10b of the 'ylindrical Lpawlwhereby therack and is so positioned that it serves jas'. a sup- 1s a trip leverf'Y, Secured tothe' lower endfof t e rod 5i'i P gJ ,th :qpb te'e dfq which is attached tothe arin ';as" at 9; this 75' spring serving the "function of normally repermits the teeth 12 formed thereon from dropping into engagement with the forward edge of the pawl. The rear flange 16 however is bent sidewise as shown and as such permits the teeth of the rack bar'to drop into engagement with Figs. 1 and 3. i 1

In actual operation we will assume that the arm is applied to an individual who has lost one arm and that he is therefore capable of operating the trip lever 7. If the indi vidual should desire to swing the lower arm B to a certain angular position, he releases the lever 7 by pulling it rearwardly inthe direction of arrow a. This causes the cylindrical pawl to swing in the same direction, thereby moving the supporting plate 17 up into engagement with the, rackbar and simultaneously the pawl section l8-0ut ofengagement with the vteeth. of the rack; bar. The arm section B may, the moment the pawl as shown in the pawl is released, be swung'to any angular position desired and is here instantly locked byv merely, releasingthe trip lever 7 as a pull ofthespring 8 will be sufficient to restore, the cylindrical pawl to locking position. The, rack bar 11 formsa substan- 'tial connection between the two arm sections When an adjustment has beenlmade, andwill rigidly support the arm sectionsin said position as long :as. required.

By referring to F'g. 1, it will be seen that accord 19 is employed; and that this cord is attached to the trip lever 7. .This cord is passed around the back or across the chest of-the wearer and suitably secured to the opposite shoulder and will when this shoulder is moved exert a pull sufficient to swing of the teeth in the pawl is always insured the vtriplever to releasing position. Such a cord may or may not be employed as desired, but will of course be more or less necessary if an' individual has. lost both arms.

' The cylindrical pawl here shown is not only simple and substantial in construction,

biltit is readily and quicklyoperated-either by a pull on'the cord 19 or on the lever 7,

so that the device can, never fail in operation. Wlulecertain features of the presentinvention are more or less specifically illustrated, I wish it understood that various changes in form: and proportion may be resorted to, within the scope of the appended cla1ms, similarly'that the materials and fin- 'ish of the several parts employed may be such, as the experience and judgment of the manufacturer may dictate or varying uses may demand.

Having thus described my invention, what I claim and desire to secure by Letters Patent is 1 1. The combination with the upper and lower armjsection of an artificial arm and an elbow joint connecting the same, of a rack bar pivotally attached to the upper arm section and extending downwardly into the lower arm section, a tubular cylindrical member extending crosswise of the lower arm and having a limited turning movement therein, said cylinder having a pair of opposed slots formed therein through-which 80 the rack bar extends, means normally holding the cylinder ina position where'the bottom edge lot'one of the slots will engage the teeth of the rack bar, and other means for turning the cylinder to disengagethe teetln;

The combination with the upper and lower arm section of an artificial arm and an elbow joint connecting the same, of arack barpivotally attached to the uppe rarmsection and extending downwardly into the lower arm' section, of a cylindrical rotary pawl engageable'with the rack bar to rock thesame, means for normally maintaining the pawlin-locking position, and manually vactuated meanscfor releasing the pawl 3. The. combination with the upper and lower arm section ofan artificial'arm and an ,elbow: joint connecting the same, ofa rack bar pivotallyattached to the upper arm sec- .tion and extending downwardly into the lower arm section, acylindrical lever turnably' mounted in the lower arm section, opposed slots formed ,in said cylindrical member through which thelower end of the rack bar extends, a-pawl member formed in" the'cylinder engageable with the teeth oftheracl; bar, means 'for normally holding 77 the pawl member engagement with the teeth of the rack bar, and manually actuated .means for turningthe cylindricalv member tofswingthe pawl out of engagement with the teeth. i 7 4.1m a device of the character described the combination with therack bar and a ,cylindrical member through which it,.ex

tends,of a guide plate. secured inthe cylindrical member, a supportingshelf on one end of the guide plate engageable with the teeth of the, rack bar, a handle member secured to the-cylinder to impart a turnin movement thereto, and spring actuated means alsoadaptedflto imparta. turning movement thereto.

I 5 Ina device oft-the character described 1.25 a cylindrical pawl, a pair of bearing members supporting the same, opposed slots formed in the cylindrical member, a guide plate extending therethrough and secured 1n the cylindrical pawl, a bearing plate on 0 i r 5 end of the rod, and an operating lever on the opposite end of the rod.

6. In a device of the character described the combination with the rack bar and the tubular cylindrical member through which 10 the rack bar extends, of a guide plate secured in the cylindrical member and extending therethrough, a supporting shelf on one end of, the guide plate adapted to support the teeth of the rack bar, spring actuated means adapted to impart a' turning movement to the cylindrical sleeve in one direction, and other means forimparting a turning movement to said sleeve in the opposite direction. I e

DAVID W. DORRANCE. 

